1. Field of the Invention
The present invention relates to a write-once optical disc and an apparatus and method for recording/reproducing management information on/from the optical disc.
2. Discussion of the Related Art
As an optical recording medium, optical discs on which high-capacity data can be recorded are widely being used. Among them, a new high-density optical recording medium (HD-DVD), for example, a Blu-ray disc, has been recently developed for recording and storing high-definition video data and high-quality audio data for a long-term period.
The Blu-ray disc involves the next generation HD-DVD technology and is the next generation optical recording solution, which has an excellent capability to store data more than existing DVDs. Recently, a technical specification of an international standard for HD-DVD has been established. Various standards for Blu-ray discs are being prepared. Particularly the standards for a write-once Blu-ray disc (BD-WO) are being proposed.
FIG. 1 schematically illustrates the structure of a recording area of a rewritable Blu-ray disc (BD-RE) according to a related art. As shown in FIG. 1, the disc is divided into a lead-in area, a data area and a lead-out area, starting from an inner radius thereof. Further, the data area is provided with an inner spare area (ISA) and an outer spare area (OSA) respectively disposed at the inner and outer radiuses to replace defective areas, and a user data area provided between the spare areas to record user data therein.
If a defective area is generated in the user data area while data is recorded on the rewritable Blu-ray disc (BD-RE), data is transferred from the defective area to the spare area to replace and record data in the spare area. This portion of the spare area is known as a replacement area for replacing the defective area. Additionally, position information related to the defective area, that is, position information on the defective area and on the corresponding replacement area is recorded in defect management areas (DMA1, DMA2, DMA3, and DMA4), which are provided in the lead-in/out areas, to perform defect management. The BD-RE has a cluster as a minimal recording-unit. One cluster has a total of 32 sectors, and one sector has 2048 bytes.
Since rewriting can be performed in any area of the BD-RE, the entire area of the disc can be randomly used irrespective of a specific recording manner. Also, since the defect management information can be written, erased and rewritten in the defect management areas (DMAs), it does not matter that the size of the defect management area is small. In particular, the BD-RE allocates and uses 32 clusters for each of the defect management areas (DMAs).
On the other hand, in a write-once disc such as a BD-WO, writing can be only made once in a specific area of the disc and thus, the manner of recording is much limited. As such, defect management becomes one of the important matters when data is to be recorded on a high-density write-once disc such as a BD-WO. Accordingly, the write-once disc requires a management area to record therein information on defect management and on disc management. In this regard, the write-once optical disc requires a larger management area for recording information on the defect management and on the disc use state due to its unique ‘write-once’ characteristic.
However, a unified standard satisfying the above requirements is not available for a write-once disc such as a BD-WO. Further, any standard related to presently declared write-once optical discs cannot solve the above drawbacks.